The present invention relates to a method of attaching solderable wires from individual electronic components mounted on a PC board to a lead frame and particularly relates to a novel method of soldering the wires. The present invention also relates to a PC board supported on a fixture for facilitating the soldering.
Electronic components such as ferrite toroids are mounted on a PC board. Each component has a lead wire, e.g., a magnet wire (another name for insulated copper wire) wound on the ferrite toroid.
Traditionally, solderable wires, e.g., magnet wires, extend to respective pins on the electronic component PC board and are hand wrapped around the pins and then hand soldered in place with a soldering iron. The hand wrapping of wires and hand soldering presents numerous problems, including inconsistencies of manufacture. For example, wrapping magnet wire by hand around a pin on a board requires pulling the wire for creating tension to insure proper attachment. The tension varies depending on the person wrapping the wire and may vary with each person from time to time. As a practical result, there is inconsistency in the wire wrapping and in the tension of the wrapped wire about the pin.
Other problems sometimes encountered with hand wrapping include the need to pre-tin the magnet wire in order to remove varnish insulation from the surface of the magnet wire prior to hand wrapping the wire on a pin. Further, hand wrapping and hand soldering are laborious and time consuming, requiring individual attention to each pin.
Hand soldering produces numerous other problems such as the potential damage to the copper core of the magnet wire. Direct contact of the soldering iron with a magnet wire creates further risk of damage. Moreover, hand soldering is subject to inefficiencies as well as inconsistencies due to the duration of contact with the soldering iron and the variability of temperature of the solder iron inherent in a hand soldering process.
Using hand soldering, it is difficult to monitor the process to achieve uniformity, quality and reliability, because hand soldering is operator dependent. Thus, variations occur from operator to operator and even in work performed over a period of time by a single operator.